Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750759AbWHKHzX (ORCPT ); Fri, 11 Aug 2006 03:55:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750763AbWHKHzX (ORCPT ); Fri, 11 Aug 2006 03:55:23 -0400 Received: from embla.aitel.hist.no ([158.38.50.22]:22727 "HELO embla.aitel.hist.no") by vger.kernel.org with SMTP id S1750759AbWHKHzW (ORCPT ); Fri, 11 Aug 2006 03:55:22 -0400 Message-ID: <44DC3726.1070303@aitel.hist.no> Date: Fri, 11 Aug 2006 09:52:06 +0200 From: Helge Hafting User-Agent: Thunderbird 1.5.0.4 (X11/20060713) MIME-Version: 1.0 To: Edgar Toernig CC: Alan Cox , Chase Venters , Pekka Enberg , Pavel Machek , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, akpm@osdl.org, viro@zeniv.linux.org.uk, tytso@mit.edu, tigran@veritas.com Subject: Re: [RFC/PATCH] revoke/frevoke system calls V2 References: <20060805122936.GC5417@ucw.cz> <20060807101745.61f21826.froese@gmx.de> <84144f020608070251j2e14e909v8a18f62db85ff3d4@mail.gmail.com> <20060807224144.3bb64ac4.froese@gmx.de> <1155039338.5729.21.camel@localhost.localdomain> <20060809104159.1f1737d3.froese@gmx.de> <1155119999.5729.141.camel@localhost.localdomain> <20060809200010.2404895a.froese@gmx.de> In-Reply-To: <20060809200010.2404895a.froese@gmx.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 957 Lines: 21 Edgar Toernig wrote: [...] > I wasn't aware of that (and I would definitely prefer a different behaviour). > > But anyway, correct me if I'm wrong, revoke (V2) not simply removes the > pages from the mmaped area as truncating does (the vma stays); revoke > seems to completely remove the vma which is clearly a security bug. > Future mappings may silently get mapped into the area of the revoked > file without the app noticing it. It may then hand out data of the new > file still thinking it's sending the old one. > One could remap to /dev/null - the file would then be free to be umounted, but the app could get confused. Or map inaccessible pages, so the app segfault on the next access. Helge Hafting - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/